Rapid permeation of sucrose into rice callus cells as a component of cryoprotectant solutions

Sucrose was first included in plant vitrification solutions (PVS) in 1989
and has since remained a primary component of most formulations. Although
sucrose is known to stabilize cell membranes, prevent protein
denaturation, and promote cellular dehydration, its specific role in
successful plant cryopreservation remains unclear. The study reported here
evaluates sucrose permeation into rice callus cells for each step of a
model cryopreservation cycle. By deuterating sucrose, its C–D bond can be
tracked using coherent anti‑Stokes Raman scattering microscopy, a highly
sensitive, non‑invasive vibrational microscopy technique, thus converting
the molecule into its own imaging agent. Results show that sucrose
permeates cells quickly, within 6 s of initial exposure, and takes only
20‑30 s to reach steady‑state concentration. Sucrose also permeates the
cells regardless of pre‑existing intracellular sucrose from prior exposure
in the model cryopreservation cycle. Beyond the permeation of sucrose as a
cryoprotecting agent, the results presented here suggest that this method
could measure permeation by sucrose into biological tissue or
biomaterials, and can be extended to other molecules, such as the
permeation of herbicides or drugs, showing kinetics and sequestration into
live cells and tissue.